The
new twenty dollar bill was released in 1998 with new features designed
to protect against counterfeiting. The portrait of Andrew Jackson has
been enlarged and given more detail so that it is both easier to recognize
and harder to duplicate. The "20" in the lower right corner is printed
with color shifting ink. When looking at it directly it appears green,
whereas at an angle it appears black. The microprinting under the portrait
and in the "20" is also a deterrent to counterfeiters because it is
hard to replicate.
T.J. Garza
Government Treasury Site